What's the appeal of an aluminum engine block?

[razerwire]

Don't know much of anything but FWIW had a surprise when Rex Racing Engines dynoed refresh of engine out of Bennett car. When I took engine out of car and took it to them it was 427 cast iron block with mr cast iron heads. They had built engine 20 years ago and it made 450 hp with 1- 4 barrel carb on sidewinder intake. I have 2 extra sets of TWM 8 stack fuel injection setups so they suggested lets put one on and get rid of one four barrel setup. Engine had cast crank out of 428 so it was 454 cubic inches? I had billet crank setting in there shop already and had planned to put it in already. Surprise came when on dyno, it put out 357 hp a 3500 rpm and 532 lbs tq. tq climbed to 633 lbs at 4800 rpm and hp 658 at 5900 rpm. Big surprise because all aluminum shelby block and heads in csx car built by Kroyer Engines, 468 cubic inch, was not much different. 660 hp with 560 lbs tq. REx Engines suggested new Edelbrock heads on cast iron block so that what was used. I have to agree with post's by builders here that iron block seams way to go. Also have to say that I have had no trouble with leaks or engine built by Kroyer. Have set of dove mr heads if any one has interest and also 1 set of mr cast iron heads if someone has interest. Will keep two side oiler 427 blocks for what idk.

[Large Arbor]

If Shelby has alloy blocks available, what's the big deal/ If you want one drop the $6-7k and send it to a reputable builder and don't worry about it. I can say that my block, #597 has performed well and I would drop the $ I did on the ERA with aluminum block again. Great value, great performance, and great resale.

Phil

[RodKnock]

Originally Posted by Large Arbor

If Shelby has alloy blocks available, what's the big deal/ If you want one drop the $6-7k and send it to a reputable builder and don't worry about it. I can say that my block, #597 has performed well and I would drop the $ I did on the ERA with aluminum block again. Great value, great performance, and great resale.

Phil

I'd entertain the idea of dropping in an LS9, depending on how much hardship there was installing it or whatever LSx series that mates up to Tremec TKO600 easily enough. If it's good enough for the Aussies, then it's good enough for me.

LS9 Crate Engine - Race Engine | Chevrolet

Aussie, Aussie, Aussie, oy, oy, oy.

[RockBit]

The Shelby website lists the current price for their aluminum block as $7245.95. Up from $6900. A few months ago.

[Dimis]

Originally Posted by RockBit

The Shelby website lists the current price for their aluminum block as $7245.95. Up from $6900. A few months ago.

...and with it the price and appeal of those cobras with Alu engines seems to keep climbing

Originally Posted by patrickt

On Dimis' patent thingy, it's not my area of expertise, but I can at least look it up for you geniuses.

PS: ...and in case you all were wondering, it's genii
Thanks for the link.

[Antny]

Scoffing at extra power, or shaving weight.....i had to check if I was really on a Cobra forum. ;-)

[ERANJ]

Based upon the feedback from the hands-on technical experts in terms of reliability, quality and power output an iron block is preferred. From my personal experience FEs are temperamental enough without adding another variable to the equation.

It also depends on the type of build you’re seeking and Cobra manufacture. For some of the replicas I feel an aluminum block is probably the easiest and best path forward provided the cost is not a concern. For builds where the purpose of an old school is the intention I can see a cast iron block is preferred.

So to say an aluminum block is more desirable for resale or worth more depends on the particular car IMO. Everyone has their preference/opinion but would not make an overall claim about aluminum.

[Detroit Bill]

This is an interesting conversation to have at this point. Did you have this conversation with all the previous Aluminum block customers you build engines for?

[blykins]

A lot of guys will ask about the differences between materials and I think I try to mention it to those that don't.

However, there were engines that were built before I experienced a few quality issues and hassles. Kind of a straw that broke the camel's back type of thing. At some point, you just have to stand back and say, "I just don't feel like doing that anymore."

[Detroit Bill]

Originally Posted by blykins

A lot of guys will ask about the differences between materials and I think I try to mention it to those that don't.

However, there were engines that were built before I experienced a few quality issues and hassles. Kind of a straw that broke the camel's back type of thing. At some point, you just have to stand back and say, "I just don't feel like doing that anymore."

That's interesting. Given my time back I would have considered a iron block.
I would want to be able to get to 482 CI though.

It is a toy, not a life saving medical device.

[blykins]

Of course no one is going to complain. It's because all the risks are taken by the engine builders before the customer even sees it. All the customer knows is that they have an all-aluminum engine.

You haven't heard anyone mention that aluminum blocks are fickle? Did you read any of the posts by Barry or myself? You have seen a sample of one engine. I've got a sample size much larger than that....

Starbucks tastes like automatic transmission fluid. (Yes, I've tasted both.)

We know you like your engine. That's perfectly fine. I'm not building any more of them, hence the original post from 11 pages back....

[RodKnock]

Originally Posted by blykins

Of course no one is going to complain. It's because all the risks are taken by the engine builders before the customer even sees it. All the customer knows is that they have an all-aluminum engine.

You haven't heard anyone mention that aluminum blocks are fickle? Did you read any of the posts by Barry or myself? You have seen a sample of one engine. I've got a sample size much larger than that....

Starbucks tastes like automatic transmission fluid. (Yes, I've tasted both.)

We know you like your engine. That's perfectly fine. I'm not building any more of them, hence the original post from 11 pages back....

No, I can't remember any consumer (not engine builder) posting that their alloy block is "fickle." What does "fickle" mean? Does that mean they have to re-torque their head bolts? Don't owners of aluminum intakes (everyone) re-torque their intake bolts? According to the Shelby website, the Shelby alloy block is even stronger than the original cast iron FE block.

To a "hot rodder", weight savings is a crucial factor when purchasing parts, probably since cavemen inhabited the Earth. Cavemen and cavewomen would search far and wide for a lighter, but strong, club to hit other cavemen with. If you read the Porsche forums, those guys and gals take out their airbags to reduce weight, change wheels and seats, etc., that's how obsessed they are weight savings.

Yes, I was kidding about Starbucks coffee. Worst coffee ever. BUT! it's a helluva stock to have in your portfolio. About a 2% dividend and over the past 5 years SBUX has almost tripled in value.

[moore_rb]

Originally Posted by RodKnock

If you read the Porsche forums, those guys and gals take out their airbags to reduce weight, change wheels and seats, etc., that's how obsessed they are weight savings.

Well, yeah, but it's more important for the Porsche guys to obsess about weight (and more importantly, about weight distribution)...

It wouldn't be such a big deal to them, if the Germans hadn't deliberately designed their cars to run around backwards...

just teasin'

[RodKnock]

Originally Posted by moore_rb

Well, yeah, but it's more important for the Porsche guys to obsess about weight (and more importantly, about weight distribution)...

It wouldn't be such a big deal to them, if the Germans hadn't deliberately designed their cars to run around backwards...

just teasin'

I'm having fun! I hope everyone else is too.

BTW, Happy Thanksgiving everyone.

[RodKnock]

Originally Posted by blykins

Of course no one is going to complain.

I call BS on this statement. Oh come on, you don't think we're a nation of complainers and whiners? I'd be first in line to moan about nearly everything. You name it, I'll moan about it.

Today's "groan" here on CC? Others making global statements about the "reliability, power and quality" of an alloy block versus a cast iron block when at least 8 of 9 (jkg2101 excepted) chose alloy over cast iron for the 125 lbs weight savings.

Here's my global statement (maybe a question) for the day. Why in the world would "you" drop an engine with a cast iron block into a Kirkham or alloy CSX? Aren't all the alloy bodied Cobra owners afraid that their alloy bodies might require more maintenance, dent more easily, etc.? Aren't alloy bodies more "fickle" than fiberglass bodies? Don't lean against it? Don't drop any tools on it? And if you own a BNL (bare naked lady), HOLY COW, the extra work to keep it polished is ENORMOUSLY time consuming (it's not). Aluminum is quite "fickle."

IMO, there's a disconnect of grand proportions there.

[blykins]

Fickle means that they have a greater chance of developing leaks. Fickle means that there are warm-up and operating guidelines that are a little more strict because of bearing clearance.

A Shelby block is stronger than an original FE block. Not stronger than an aftermarket cast iron block. You do have reduced ring seal from the aluminum block just because things move around so much.

We're not driving Porsches.

Thanks for the 11 pages of backing-and-forthing. I feel better.

[patrickt]

Originally Posted by blykins

Thanks for the 11 pages of backing-and-forthing. I feel better.

Now, if you would just do exactly as I tell you, you will be healthier, wealthier and wiser than RodKnock will ever be.

[RodKnock]

Originally Posted by patrickt

Now, if you would just do exactly as I tell you, you will be healthier, wealthier and wiser than RodKnock will ever be.

I don't think so.

Why does everyone post in 3's? That's another complaint of mine. There was "power, reliability and quality" and now Patrick is posting "healthier, wealthier and wiser." What's up with that? Do all of you have OCD or something?

[patrickt]

Originally Posted by RodKnock

Why does everyone post in 3's?

Because it stems from the three ethical principles of Zoroastrianism. Simple, really.

[Dimis]

I go to sleep and wake up to - BOOM! 4 more pages of fun.

I'd still choose an all AL engine, not because I'm really going to notice the difference driving, I doubt I'd notice 100HP less, but merely because it was an advancement on iron. I use the term advancement here because its lighter and does the same job. If a billet block was available, I'd have gone for that too.

Given the choice, I also wouldn't swap it for an iron build.

If I was planing a truck, sure, I'd no issue with an Iron block. But in a car that's claim to fame is BIG Engine in Light Car, then maximising the philosophy is what I'd try to do. AL block is therefor fit for purpose. True, there are lighter big engines, but for those keen on keeping an FE under the hood, then those are ones choices.

Originally Posted by RodKnock

You're making the Pond and Shelby blocks sound like Pepsi/Coke cans. People use aluminum pistons, rods, cylinder heads, intakes, rocker arms, etc. Until I see at least a good statistical sample of equally built FE engines, built with both cast iron and aluminum blocks, I call BS.
"

Hey RK just a little note for you, they are recycled Pepsi & Coke cans.

The theory does suggest that for the exact same build, Iron block will make more HP. If nothing else, simply because they have a higher density there is less distortion during detonation.
In simple terms, when the fuel goes boom, on a microscopic level there is less flex in the cylinder wall. This flex is potentially amplified the bigger the boom. Hence the claim for larger gains in HP with iron at the higher numbers, and why Barry opts for iron when building for Engine Masters Challenge (EMC). It's fit for purpose, its on an engine stand, so who cares how much it weighs?

This doesn't mean that AL Blocks can't be made to achieve the same HP numbers as iron block, its just more effort in prep and technology, and in the end, in the range we are discussing for a cobra, a few HP is mostly irrelevant. If one wanted more HP one would look at a 385 series BBF.

YES. They use AL for pistons, rods, cranks and other moving parts, because the a reduction in weight is amplified when trying to overcome inertia. Distance of weight from the Centre of Mass (CoM) is relevant in moving parts.
Weight alone is not everything, the distribution of the weight plays a factor.

In simple terms some of the energy that otherwise goes into microscopically flexing an AL Piston head, during the explosion in the cylinder, is outweighed by the gains in overcoming the lighter weight of these parts, particularly as these parts have most of their way a fair distance away from their CoM.

Reducing the weight of moving parts by "x" has a much greater impact that simply removing "x" from a non-moving part. The same logic applies and explains why one tries to minimise unsprung weight in suspensions, or the desire for Magnesium wheels, and so forth. Fit for purpose.

Enjoy...

Originally Posted by blykins

I would think that a $$$$ "aftermarket" block would be an ego-booster. Not solely focused on aluminum.

If the Cup guys can go 200 mph at 9500 with a cast iron block, you guys can drive 5 miles to Starbucks without nosing over and missing your turn......

PS: Brent Its at Starbucks speed where I notice the lighter engine most. It's easier to turn those front wheels while parking baby!

Originally Posted by patrickt

Because it stems from the three ethical principles of Zoroastrianism. Simple, really.

Patrick is in one of those moods again... Making me laugh, and educating me at the same time. Thanks Professor, I had to google that.